CN112237038A

CN112237038A - Signal pre-processing

Info

Publication number: CN112237038A
Application number: CN201880093995.7A
Authority: CN
Inventors: 骆喆; 陶涛; 刘建国; 沈钢; 王钧; 武卓; 孟艳
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Oyj
Priority date: 2018-05-30
Filing date: 2018-05-30
Publication date: 2021-01-15
Anticipated expiration: 2038-05-30
Also published as: WO2019227356A1; CN112237038B

Abstract

Embodiments of the present disclosure relate to a method, a transmitter, and a computer-readable storage medium for signal pre-processing. In an example embodiment, a transmitter generates multiple versions of a signal for transmission over multiple bandwidth portions. The transmitter selects a bandwidth portion from the plurality of bandwidth portions and then selects a version to be transmitted on the selected bandwidth portion from the plurality of versions of the signal. The transmitter transmits the selected version of the signal over the selected portion of bandwidth. In this way, the time delay between selection of BWP and transmission of the signal may be reduced.

Description

Signal pre-processing

Technical Field

Embodiments of the present disclosure relate generally to the field of signal processing, and in particular, to a method, transmitter, and computer-readable storage medium for signal pre-processing.

Background

For New Radios (NR), it is agreed that the maximum channel bandwidth per NR carrier is up to 400 MHz. The bandwidth may be divided into a plurality of bandwidth parts (BWPs). A User Equipment (UE) may be configured to operate on one or more (continuous or discontinuous) BWPs. Conventionally, BWP configuration for a UE is not dynamic on the licensed band in NR. For example, a gigabit node b (gnb) can configure uplink and downlink BWPs specific to each UE by activating or deactivating the BWPs with Radio Resource Control (RRC) signaling or Downlink Control Information (DCI). To enable switching between different BWPs in the licensed band, several time slots are defined for generating the signal to be transmitted.

Unlicensed bands have become a beneficial complement to licensed bands to meet the growing service requirements. In the European Telecommunications Standards Institute (ETSI) standardization for unlicensed frequency bands, it is proposed that an unlicensed frequency band be divided into a plurality of operating channels, and a device may simultaneously occupy a plurality of continuous/discontinuous operating channels. For example, the unlicensed spectrum 5150MHz to 5350MHz may be divided into 10 operating channels, i.e., 20MHz per channel. Each operating channel may be considered to be a large bandwidth BWP of the unlicensed band. By using a single Radio Frequency (RF) transmit (Tx)/receive (Rx) chain that switches between different operating channels, the UE and the gNB may operate on an unlicensed band with a large bandwidth.

On the unlicensed band, some operating channels may already be occupied by some devices, while one device may not occupy the entire unlicensed band. Dynamic BWP adaptation is proposed for unlicensed NRs, taking into account the variation of the available operating channels over time. In dynamic BWP adaptation, a device performs transmissions on idle BWPs and automatically discards busy BWPs to improve unlicensed spectrum efficiency. For example, a device may perform Listen Before Talk (LBT) or Clear Channel Assessment (CCA) procedures to detect for a clear BWP for a transmission.

However, such dynamic BWP adaptation to the unlicensed bandwidth requires a high processing performance of the sender in terms of processing time, processing speed, and the like.

Disclosure of Invention

In general, example embodiments of the present disclosure provide a method, a transmitter, and a computer-readable storage medium for signal pre-processing.

In a first aspect, a method at a transmitter is provided. A plurality of versions of the first signal are generated for transmission over the plurality of bandwidth portions. The method further includes selecting a bandwidth portion from the plurality of bandwidth portions and selecting a version of the first signal to be transmitted on the selected bandwidth portion from the plurality of versions of the first signal. The selected version of the first signal is then transmitted over the selected portion of the bandwidth.

In a second aspect, a transmitter is provided that includes at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform the method according to the first aspect.

In a third aspect, a computer-readable storage medium is provided on which a computer program is stored. The computer program, when executed by a processor, causes the processor to perform the method according to the first aspect.

It should be understood that this summary is not intended to identify key or essential features of the embodiments of the disclosure, nor is it intended to be used to limit the scope of the disclosure. Other features of the present disclosure will become readily apparent from the following description.

Drawings

Some example embodiments will now be described with reference to the accompanying drawings, in which:

FIG. 1 illustrates three example cases of dynamic BWP adjustment;

FIG. 2 illustrates an example environment in which embodiments of the present disclosure may be implemented;

fig. 3 illustrates an example arrangement of a transmitter for generating a time-domain baseband version of a first signal, in accordance with some embodiments of the present disclosure;

fig. 4 illustrates another example arrangement of a transmitter for generating a time-domain baseband version of a first signal, in accordance with some other embodiments of the present disclosure;

fig. 5 illustrates an example process implemented at a transmitter, in accordance with some embodiments of the present disclosure;

FIG. 6 illustrates a flow diagram of an example method according to some embodiments of the present disclosure; and

fig. 7 illustrates a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numbers refer to the same or similar elements.

Detailed Description

The principles of the present disclosure will now be described with reference to a few exemplary embodiments. It is understood that these embodiments are described for illustrative purposes only and are presented to aid those skilled in the art in understanding and enabling the present disclosure and are not intended to suggest any limitation as to the scope of the present disclosure. The disclosure described herein may be implemented in various ways other than those described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

As used herein, the term "transmitter" refers to a device capable of transmitting a signal. As used herein, the term "receiver" refers to a device capable of receiving a signal. The transmitter or receiver may be implemented by or as part of any suitable device, including, for example, a network device or a terminal device.

As used herein, the term "network device" refers to any suitable device on the network side of a communication network. The network device may comprise any suitable device in an access network of a communication network, including, for example, a Base Station (BS), a relay, an Access Point (AP), a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a gigabit NodeB (gnb), a remote radio module (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a low power node (such as a femto node, pico node), and the like.

As used herein, the term "terminal device" refers to a device that is capable of being configured, arranged and/or operable to communicate with a network device or another terminal device in a communication network. The communication may involve the transmission and/or reception of wireless signals using electromagnetic signals, radio waves, infrared signals, and/or other types of signals suitable for the transmission of information over the air. In some embodiments, the terminal device may be configured to transmit and/or receive information without direct human interaction. For example, when triggered by an internal or external event, or in response to a request from the network side, the terminal device may transmit information to the network device on a predetermined schedule.

Examples of end devices include, but are not limited to, User Equipment (UE), such as a smart phone, a wireless enabled tablet, a laptop embedded device (LEE), a laptop installed device (LME), and/or a wireless Customer Premises Equipment (CPE). For discussion purposes, some embodiments will be described with reference to a UE as an example of a terminal device, and the terms "terminal device" and "user equipment" (UE) may be used interchangeably in the context of this disclosure.

As used herein, the term "circuitry" may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog circuitry and/or digital circuitry); and

(b) a combination of hardware circuitry and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuit(s) and software/firmware, and (ii) any portion of hardware processor(s) with software, including digital signal processor(s), software, and memory(s), that operate together to cause a device such as a mobile telephone or server to perform various functions; and

(c) hardware circuit(s) and/or processor(s), such as microprocessor(s) or a portion of microprocessor(s), that require software (e.g., firmware) to operate but may not be present when software is not required to operate.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also encompasses implementations that are part of a hardware circuit or processor (or multiple processors) alone or in combination with software and/or firmware accompanying it (or them). For example and where applicable to particular claim elements, the term circuitry also encompasses baseband or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "include" and its variants are to be read as open-ended terms, which mean "including, but not limited to". The term "based on" will be read as "based, at least in part, on". The terms "one embodiment" and "an embodiment" are to be read as "at least one embodiment". The term "another embodiment" will be read as "at least one other embodiment". Other definitions (explicit and implicit) may be included below.

On the unlicensed band, dynamic BWP adjustment is required to allow transmission of multiple devices. For example, prior to transmission, a device may first detect an idle BWP during an LBT or CCA procedure.

Fig. 1 shows three example cases of dynamic BWP adjustment. In these cases (e.g., case 1, case 2, or case 3), four consecutive BWPs 105 are configured to one device. In case 1, during the CCA procedure, the device detects that the first BWP 110-1 and the fourth BWP125-1 are blocked due to being occupied by other devices. The second BWP 115-1 and the third BWP 120-1 are detected as clear and available. In this case, the device may transmit using the second BWP 115-1 and the third BWP 120-1.

In case 2, the fourth BWP 125-2 is blocked. The first BWP 110-2, the second BWP 115-2, and the third and BWP 120-2 are unobstructed and available to the device. In case 3, the second BWP 115-3 and the fourth BWP 125-3 are blocked, while the first BWP 110-3 and the third BWP 120-3 are available.

Such dynamic BWP adjustment presents a number of challenges. One challenge is directed to the time at which the time-domain baseband signal is generated. Traditionally, it has been proposed that the time gap between completion of the CCA procedure and transmission does not exceed 16 us. In this case, since the BWP that can be actually used is obtained based on the CCA procedure, it is necessary to generate a time-domain baseband signal to be transmitted over the BWP within 16 us. The generation of the time-domain baseband signal may include a process of Inverse Fast Fourier Transform (IFFT) and filtering. However, the processing performance of current Digital Signal Processing (DSP) Integrated Circuits (ICs) cannot meet the requirements for dynamically generating time-domain baseband signals within 16 us.

In Long Term Evolution (LTE) Licensed Assisted Access (LAA), some preamble transmission schemes provide for transmission of a preamble after the CCA procedure is completed. The transmission of the preamble is used to reserve the channel prior to the transmission of the data. However, these solutions do not solve the problem of delay in signal generation during dynamic BWP adjustment.

Embodiments of the present disclosure provide a signal pre-processing scheme for dynamic BWP adjustment. With this pre-processing scheme, multiple versions of the signal are prepared in advance for transmission over multiple BWPs. Each of these versions corresponds to one of the BWPs. After selecting the BWP for transmission, the corresponding version of the signal is selected and then transmitted on the selected BWP. This preparation of multiple versions of the signal significantly reduces the time delay between selection of BWP and transmission of the signal.

FIG. 2 illustrates an example environment 200 in which embodiments of the present disclosure may be implemented. Environment 200, as part of a communication network, includes a transmitter 210 and a receiver 220. It should be understood that one transmitter and one receiver are shown for illustrative purposes only and are not intended to suggest any limitation as to the scope of the disclosure. Environment 200 may include any suitable number of transmitters and receivers suitable for implementing embodiments of the present disclosure.

Transmitter 210 and receiver 220 may be implemented by or as part of any suitable device. In some embodiments, transmitter 210 may be implemented at a network device, while receiver 220 may be implemented at a terminal device, and vice versa. In embodiments where environment 200 is part of a relay communication network, in this example, transmitter 210 may be implemented at a network device and receiver 220 may be implemented at a relay, and vice versa. In some other embodiments, both the transmitter 210 and the receiver 220 may be implemented at a terminal device in device-to-device (D2D) communication, which D2D communication may alternatively be referred to as a side link, or vehicle association (V2X).

The transmitter 210 may communicate with the receiver 220. The communication may follow any suitable communication standard or protocol, such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), LTE-advanced (LTE-a), fifth generation (5G) NR, wireless fidelity (Wi-Fi), and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employ any suitable communication technology including, for example, multiple-input multiple-output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), Code Division Multiplexing (CDM), bluetooth, ZigBee, and Machine Type Communication (MTC), enhanced mobile broadband (eMBB), large scale Machine Type Communication (MTC), and ultra-reliable low latency communication (urrllc) technologies.

Transmitter 210 may transmit signals to receiver 220 over multiple BWPs, e.g., configured by a network. BWP may be a portion of a licensed band or an unlicensed band. For purposes of discussion, some embodiments are discussed in the context of unlicensed BWP.

Prior to transmission of the signal (referred to as the first signal), transmitter 210 generates multiple versions of the first signal for transmission over multiple BWPs. In some embodiments, the plurality of versions are a plurality of time domain baseband versions. A plurality of time-domain baseband versions may be generated from a plurality of frequency-domain baseband versions of the first signal.

Fig. 3 illustrates an example arrangement 300 of a transmitter 210 for generating a time-domain baseband version of a first signal, in accordance with some embodiments of the present disclosure. In this example, the first signal is a preamble based on a Zadoff-chu (zc) sequence, as shown. Other implementations of the first signal are also possible. For example, the first signal may be part of a data burst.

The arrangement 300 includes a ZC sequence generator 305 for generating ZC sequences based on a root and cyclic shifts. For example, the generated ZC sequence may be 599 in length. The ZC sequence is input into a serial-to-parallel converter 310 for converting a serial input sequence into a parallel output sequence. The parallel sequences are input into a Fast Fourier Transformer (FFT)315 for Discrete Fourier Transform (DFT) spreading in the frequency domain.

The DFT spread sequences of the ZC sequence may be mapped to a plurality of BWPs to form a plurality of frequency domain baseband versions of the first signal. In this example, four consecutive BWPs (BWP #0, 1, 2 or 3) are configured and each BWP corresponds to a 20MHz operating channel with a subcarrier spacing (SCS) of 30 kHz. Arrangement 300 includes four switches 320-1, 320-2, 320-3, and 320-4 for enabling respective BWP #0, 1, 2, and 3 by controlling input sequences into an Inverse Fast Fourier Transform (IFFT) 325.

For example, to generate a version to be sent on BWP #0 and 1, switches 320-1 and 320-2 for BWP #0 and 1 are opened and switches 320-3 and 320-4 for BWP #2 and 3 are closed. The inputs to IFFT 325 are fed with zero values for BWP #2 and 3 that are disabled. The multiple versions may be generated by combining and repeatedly turning on/off switches for respective BWPs.

The output of the IFFT 325 is input into a parallel-to-serial converter 330 for converting the parallel sequence into a serial sequence. The output serial sequence of the parallel to serial converter 330 is filtered by a filter 335 to generate a time domain baseband version of the first signal. In this example, the time-domain baseband version occupies one OFDM symbol. The time-domain baseband version may occupy any number of OFDM symbols depending on the width of the subcarriers and BWP.

Fig. 4 illustrates another example arrangement 400 of a transmitter 210 for generating a time-domain baseband version of a first signal, according to some other embodiments of the present disclosure. In this example, the first signal is a preamble based on a pseudo-random sequence (e.g., a length-31 Gold sequence), as shown.

In arrangement 400, a pseudo-random sequence generator 405 generates a pseudo-random sequence after initialization. The pseudo-random sequence is input into a serial-to-parallel converter 410 for converting a serial input sequence into a parallel output sequence. The parallel output sequence is mapped successively to all four consecutive BWP #0, 1, 2 and 3. Switches 415-1, 415-2, 415-3, and 415-4 then enable the respective BWP by puncturing Resource Elements (REs) of the BWP.

The outputs of switches 415-1, 415-2, 415-3, and 415-4 are coupled to the inputs of IFFT 420. When BWP is off, the output of the switch for BWP is set to zero. The parallel sequence output by IFFT420 is converted to a serial sequence by parallel-to-serial converter 425, and then the serial sequence is filtered by filter 430 to generate a time-domain baseband version of the first signal, which occupies one OFDM symbol.

In various embodiments of the present disclosure, after the multiple versions of the first signal are generated, the transmitter 210 selects one BWP from the multiple BWPs for transmission. In some embodiments, a BWP may be selected by detecting an idle BWP from among a plurality of BWPs, for example, during a CCA procedure for the unlicensed band.

A version of the first signal corresponding to the selected BWP is selected from the generated versions and then transmitted on the selected BWP. Pre-generating multiple versions of the first signal reduces the time delay between selection of the BWP and transmission of the first signal.

In some embodiments, regardless of the CCA result, multiple versions of the first signal may be prepared only once and reused in subsequent transmissions. In this way, the complexity of the transmitter 210 may be further reduced.

Fig. 5 illustrates an example process 500 implemented at the transmitter 210, in accordance with some embodiments of the present disclosure. In this example, four consecutive BWPs 505-1, 505-2, 505-3, and 505-4 are configured. The configuration is known to both the transmitter 210 and the receiver 220.

The transmitter 210 prepares (510) multiple time domain baseband versions of a first signal (e.g., a preamble) for different CCA results. The time domain baseband version occupies one OFDM symbol.

During the CCA procedure (515), the transmitter 210 detects that BWPs 505-1 and 505-2 are available and BWPs 505-3 and 505-4 are blocked. The transmitter 210 selects (520) the version corresponding to BWPs 505-1 and 505-2, for example, within 16us based on the CCA results. The selected version of the first signal is transmitted (525) on BWPs 505-1 and 505-2.

After the transmission of the first signal is completed, a subsequent signal (referred to as a second signal) is sent on BWPs 505-1 and 505-2 (530). The second signal may be any suitable signal that is transmitted after the first signal. In embodiments where the first signal is a preamble, the second signal may be a data burst. In some embodiments, as shown, during transmission of the first signal, the transmitter 210 may generate (528) a second signal to be transmitted on the selected BWPs 505-1 and 505-2 for further reducing processing delay.

At receiver 220, the BWP used by transmitter 210 may be determined by detecting the first signal from transmitter 210. In some embodiments, the first signal may include an indication for the second signal to facilitate reception of the second signal at receiver 220. For example, the indication may comprise an indication of a length of the second signal.

The length of the second signal may be indicated by the first signal in any suitable manner. In embodiments where the first signal is a preamble based on a ZC sequence and the second signal is a data burst, the cyclic shift of the ZC sequence may be associated with the length of a subsequent data burst. For example, a cyclic shift equal to 0 may be used to indicate a burst length of 1 slot, a cyclic shift equal to 1 may be used to indicate a burst length of 2 slots, and so on.

In an embodiment where the first signal is a Gold sequence based preamble and the second signal is a data burst, the initialization c of the second m-sequence of the Gold sequence_initIndex n which can be compared with CCA result_CCAAnd length n of data burst_burst-lengthThe following steps are involved: c. C_init＝n_CCA·2¹⁵+n_burst-length。

Based on the indication of the length of the second signal, receiver 220 may detect the second signal at the appropriate timing. In addition, other receivers may know the length of the second signal and may sleep during transmission of the second signal to improve power efficiency.

In some embodiments, at receiver 220, the first signal may include demodulation reference information for channel estimation. Based on the measurements of the first signal, receiver 220 may estimate the transmission channel for demodulation, or alternatively for the supplementation of the demodulation reference signals (DMRS) of the NR.

Fig. 6 illustrates a flow diagram of an example method 600 in accordance with some embodiments of the present disclosure. Method 600 may be implemented at transmitter 210 as shown in fig. 2.

At block 605, multiple versions of a first signal are generated for transmission over multiple bandwidth portions. At block 610, a bandwidth portion is selected from a plurality of bandwidth portions. At block 615, a version of the first signal to be transmitted over the selected portion of bandwidth is selected from a plurality of versions of the first signal. At block 620, the selected version of the first signal is transmitted over the selected portion of bandwidth.

In some embodiments, the multiple versions may be multiple time domain baseband versions. A plurality of frequency-domain baseband versions of the first signal may be first generated and then a plurality of time-domain baseband versions may be generated from the plurality of frequency-domain baseband versions.

In some embodiments, from among the plurality of bandwidth portions, a spare bandwidth portion is detected as the selected bandwidth portion.

In some embodiments, during transmission of the selected version of the first signal, a second signal may be generated to be transmitted over the selected portion of the bandwidth after the first signal.

In some embodiments, the multiple versions of the first signal may be associated with different lengths of the second signal to be transmitted over the selected portion of bandwidth after the first signal.

In some embodiments, the first signal comprises a preamble and the second signal comprises a data burst.

In some embodiments, the first signal includes demodulation reference information.

It should be understood that all operations and features related to transmitter 210 as described above with reference to fig. 2-5 are equally applicable to method 600 and have similar effects. Details will be omitted for the sake of simplicity.

In some embodiments, an apparatus capable of performing the method 600 may include means for performing the respective steps of the method 600. The component may be implemented in any suitable form. For example, the components may be implemented in a circuit or a software module.

In some embodiments, an apparatus capable of performing method 600 comprises: means for generating, at a transmitter, a plurality of versions of a first signal for transmission over a plurality of bandwidth portions; means for selecting a bandwidth portion from a plurality of bandwidth portions; means for selecting a version of the first signal to be transmitted over the selected portion of bandwidth from a plurality of versions of the first signal; and means for transmitting the selected version of the first signal over the selected portion of bandwidth.

In some embodiments, the plurality of versions are a plurality of time domain baseband versions. The means for generating the plurality of versions of the first signal may comprise: means for generating a plurality of frequency domain baseband versions of a first signal; and means for generating a plurality of time-domain baseband versions from the plurality of frequency-domain baseband versions.

In some embodiments, the means for selecting the bandwidth portion may comprise: means for selecting a bandwidth portion by detecting a free bandwidth portion from the plurality of bandwidth portions as the selected bandwidth portion.

In some embodiments, the apparatus may include means for generating a second signal during transmission of the selected version of the first signal, the second signal to be transmitted over the selected portion of the bandwidth after the first signal.

Fig. 7 is a simplified block diagram of a device 700 suitable for implementing embodiments of the present disclosure. The device 700 may be implemented at, or at least partially as part of, the transmitter 210 as shown in fig. 2.

As shown, device 700 includes a processor 710, a memory 720 coupled to processor 710, a communication module 730 coupled to processor 710, and a communication interface (not shown) coupled to communication module 730. The memory 720 stores at least a program 740. The communication module 730 is used for bidirectional communication. The communication interface may represent any interface required for communication.

The program 740 is assumed to include program instructions that, when executed by the associated processor 710, enable the device 700 to operate in accordance with embodiments of the present disclosure, as discussed herein with reference to fig. 2-6. Embodiments herein may be implemented by: the processor 710 of the device 700 may execute computer software, or hardware, or a combination of software and hardware. The processor 710 may be configured to implement various embodiments of the present disclosure.

The memory 720 may be of any type suitable to the local technology network and may be implemented using any suitable data storage technology, such as non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. Although only one memory 720 is shown in device 700, there may be several memory modules that are physically different in device 700. The processor 710 may be of any type suitable for a local technology network, and may include one or more of the following as non-limiting examples: general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs) and processors based on a multi-core processor architecture. The device 700 may have multiple processors, such as an application specific integrated circuit chip that is time dependent from a clock synchronized with the main processor.

All operations and features related to transmitter 210 as described above with reference to fig. 2-6 are equally applicable to device 700 and have similar effects. Details will be omitted for the sake of simplicity.

In general, the various embodiments of the disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the blocks, apparatus, systems, techniques or methods described herein may be implemented as non-limiting examples in the following: hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product comprises computer-executable instructions, such as those included in program modules, that are executed in the device on the target real or virtual processor to perform the method 600 as described above with reference to fig. 2-6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or divided between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local device or within a distributed device. In a distributed facility, program modules may be located in both local and remote memory storage media.

Program code for performing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowchart and/or block diagram to be performed. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Various embodiments of the techniques have been described. In addition to or in the alternative to the above, the following examples are described. Features described in any of the examples below may be utilized with any of the other examples described herein.

Claims

1. A method, comprising:

generating, at a transmitter, a plurality of versions of a first signal for transmission over a plurality of bandwidth portions;

selecting a bandwidth portion from the plurality of bandwidth portions;

selecting a version of the first signal to be transmitted over the selected portion of bandwidth from the plurality of versions of the first signal; and

transmitting the selected version of the first signal over the selected portion of the bandwidth.

2. The method of claim 1, wherein the plurality of versions are a plurality of time-domain baseband versions, and generating the plurality of versions of the first signal comprises:

generating a plurality of frequency domain baseband versions of the first signal; and

generating the plurality of time-domain baseband versions from the plurality of frequency-domain baseband versions.

3. The method of claim 1 or 2, wherein selecting the bandwidth portion comprises:

selecting the bandwidth part by detecting a spare bandwidth part from the plurality of bandwidth parts as the selected bandwidth part.

4. The method of any of claims 1 to 3, further comprising:

during the transmission of the selected version of the first signal, generating a second signal to be transmitted on the selected portion of bandwidth after the first signal.

5. The method of any of claims 1-3, wherein the multiple versions of the first signal are associated with different lengths of a second signal to be transmitted on the selected portion of bandwidth after the first signal.

6. A method according to claim 4 or 5, wherein the first signal comprises a preamble and the second signal comprises a data burst.

7. The method of any of claims 1-6, wherein the first signal comprises demodulation reference information.

8. A transmitter, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the transmitter to:

generating a plurality of versions of a first signal for transmission over a plurality of bandwidth portions;

selecting a bandwidth portion from the plurality of bandwidth portions;

9. The transmitter of claim 8, wherein the plurality of versions are a plurality of time-domain baseband versions, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the transmitter to:

10. The transmitter according to claim 8 or 9, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the transmitter to:

11. The transmitter according to any one of claims 8 to 10, the at least one memory and the computer program code further configured to, with the at least one processor, cause the transmitter to:

12. The transmitter of any of claims 8 to 10, wherein the plurality of versions of the first signal are associated with different lengths of a second signal to be transmitted on the selected portion of bandwidth after the first signal.

13. The transmitter according to claim 11 or 12, wherein the first signal comprises a preamble and the second signal comprises a data burst.

14. The transmitter according to any one of claims 8 to 13, wherein the first signal comprises demodulation reference information.

15. A computer readable storage medium having stored thereon a computer program which, when executed by a processor, causes the processor to perform acts comprising:

selecting a bandwidth portion from the plurality of bandwidth portions;

16. The computer-readable storage medium of claim 15, wherein the plurality of versions are a plurality of time-domain baseband versions, and generating the plurality of versions of the first signal comprises:

17. The computer-readable storage medium of claim 15 or 16, wherein selecting the bandwidth portion comprises:

18. The computer-readable storage medium of any of claims 15 to 17, wherein the acts further comprise:

19. The computer-readable storage medium of any of claims 15-17, wherein the multiple versions of the first signal are associated with different lengths of a second signal to be transmitted on the selected portion of bandwidth after the first signal.

20. The computer-readable storage medium of claim 18 or 19, wherein the first signal comprises a preamble and the second signal comprises a data burst.

21. The computer-readable storage medium of any of claims 15 to 20, wherein the first signal comprises demodulation reference information.